Abstract

The current paucity of published blood values and other clinically relevant data for short-beaked common dolphins (Delphinus delphis) hinders the ability of veterinarians and stranding responders to make well-informed disposition decisions regarding live-strandings of this species.^2,3 Cape Cod, MA, USA experiences one of the highest and most consistent rates of cetacean stranding in the world, with 1,320 cetaceans stranding on Cape Cod shores over the past ten years, one third of which were D. delphis.^1,2,4 This study evaluates the prognostic efficacy of 24 hematologic, 32 clinical chemistry, and five physical parameters from stranded common dolphins on Cape Cod, MA in light of their post-release survival data. All stranded common dolphin cases between January 2010 and June 2012 were reviewed and animals with known outcomes (based on satellite tag data, known death, or re-stranding) and available blood data were placed into two groups for analysis: "failed" and "survived." Twenty-six D. delphis met the criteria to be included in this study: ten animals comprised the "failed" group [3 females (30%), 7 males (70%); 3 single stranded (30%), 7 mass stranded (70%)] and sixteen comprised the "survived" group [5 females (31%), 11 males (69%); 4 single stranded (25%), 12 mass stranded (75%)]. Results indicate that failed dolphins had significantly lower hematocrit, hemoglobin, red blood cell counts, albumin, albumin-to-globulin ratios, total CO2, and bicarbonate values than those that survived. Red cell distribution width, blood urea nitrogen, uric acid, and length-to-girth ratios were significantly higher in animals that failed. In general, failed dolphins were more anemic, acidemic, and hypoalbuminemic than survivors. Additionally, the group of failed dolphins presented all of the highest values for ALT, AST, CK, LDH, GGT, and lactate. This combination of results indicates that there may be a variety of factors affecting post-release survival, including both pre-existing conditions (i.e. pneumonia and liver disease) and stranding-induced conditions such as tissue ischemia and capture myopathy. Closer evaluation of these parameters for stranded common dolphins on point of care analyzers in the field may allow stranding responders and veterinarians to make better disposition decisions for these animals in the future.

Acknowledgements

Marine mammal stranding response operations for this study were conducted under IFAW Marine Mammal Rescue and Research's Stranding Agreement with the National Oceanographic and Atmospheric Administration's National Marine Fisheries Service. The John H. Prescott Marine Mammal Rescue Assistance Program provided support for stranding response efforts during this study period. We would like to thank the Pegasus Foundation and Barbara Birdsey for their support and funding for the IFAW Satellite Tag Program. This project would not have been possible without funding from the US Army Medical Research and Material Command through Tufts Cummings School of Veterinary Medicine (TCSVM). Thanks go to Dr. Phyllis Mann of TCSVM and Dr. Bruce Barton of University of Massachusetts Medical School for providing statistical consultation. The Northeast Region Stranding Network was instrumental in providing assistance including animal care and data collection for this project, especially during the unprecedented stranding season of 2012. Finally, the authors thank the IFAW Marine Mammal Rescue volunteers for their tireless work in the field rescuing and documenting stranded dolphins.

* Presenting author
+ Student presenter

Literature Cited

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